1. Field of the Invention
The present invention relates to novel cephalosporin compounds and pharmacologically acceptable salts or esters thereof as well as antibacterial compositions comprising these compounds as the effective ingredient.
2. Description of Prior Art
Cephalosporin type antibiotics exhibit a wide antibacterial activity against gram positive bacteria and gram negative bacteria. A variety of semi-synthetic cephalosporin compounds are already commercially available and have been provided for use and clinically used as therapeutic agents for various infectious diseases. Among these compounds, however, a few therapeutic agents exert antibacterial activity against Pseudomonas aeruqinosa or slime molds. Furthermore, most of these compounds involve shortcomings in that they are unstable to .beta.-lactamase produced by resistant bacteria and have a low activity on resistant bacteria which are currently of concern clinically, etc. (cf., W.E. Wick, Chapter 11 in "Cephalosporins and Penicillins, Chemistry and Biology", edited by E.H. Flynn, Academic Press, New York, N.Y., 1972).
The present inventors previously disclosed in Japanese Patent Application Laid-Open Nos. 492/1987, 10822/1987 and 174083/1987 that cephalosporin compounds having 2-(2-amino-thiazol-4-yl)-2-(1,5-dihydroxy-4-pyridone-2-carboxamido)acetami do group at the 7-position of the cephem ring have a potent activity against pathogenic bacteria over a wide spectrum.